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open geoportal

This past weekend I had the privilege of attending the Open Geoportal (OGP) National Summit in Boston, hosted by Tufts University and funded by the Sloan Foundation. The Open Geoportal (OGP) is a map-based search engine that allows users to discover and retrieve geospatial data from many repositories. The OGP serves as the front-end of a three-tiered system that includes a spatial database (like PostGIS) at the back and some middleware (Like OpenLayers) to communicate between the two.

Users navigate via a web map (Google by default but you can choose other options), and as they change the extent by panning or zooming a list of available spatial layers appears in a table of contents beside the map. Hovering over a layer in the contents reveals a bounding box that indicates its spatial extent. Several algorithms determine the ranking order of the results based on the spatial intersection of bounding boxes with the current map view. For instance, layers that are completely contained in the map view have priority over those that aren’t, and layers that have their geographic center in the view are also pushed higher in the results. Non-spatial search filters for date, data type, institution, and keywords help narrow down a search. Of course, the quality of the results is completely dependent on the underlying metadata for the layers, which is stored in the various repositories.

The project was pioneered by Tufts, Harvard, and MIT , and now about a dozen other large research universities are actively working with it, and others are starting to experiment. The purpose of the summit was to begin creating a cohesive community to manage and govern the project, and to increase and outline the possibilities for collaborating across institutions. At the back end, librarians and metadata experts are loading layers and metadata into their repositories; metadata creation is an exacting and time-consuming process, but the OGP will allow institutions to share their metadata records in the hope of avoiding duplicated effort. The OGP also allows for the export of detailed spatial metadata from FGDC and ISO to MODS and MARC, so that records for the spatial layers can be exported to other content management systems and library catalogs.

The summit gave metadata experts the opportunity to discuss best practices for metadata creation and maintenance, in the hopes of providing a consistent pool of records that can be shared; it also gave software developers the chance to lay out their road map for how they’ll function as an open source project (the OGP community could look towards the GeoNetwork opensource project, a forerunner in spatial metadata and search that’s used in Europe and by many international organizations). Series of five-minute talks called Ignite sessions gave librarians and developers the ability to share the work they were doing at their institutions, either with OGP in particular or with metadata and spatial search in general, which sparked further discussion.

The outcome of all the governance, resource sharing, and best practices discussions are available on a series of pages dedicated to the summit, on the opengeoportal.org project website. You can also experiment with the OGP via http://geodata.tufts.edu/, Tuft’s gateway to their repository. As you search for data you can identify which repository the data is coming from (Tufts, Harvard, or MIT) based on the little icon that appears beside each layer name. Public datasets (like US census layers) can be downloaded by anyone, while copyrighted sets that the schools’ purchased for their users require authentication.

OGP is a great open source project that operates under OGC standards and is awesome for spatial search, but the real gem here is the community of people that are forming around it. I was blown away by the level of expertise, dedication, and over all professionalism that each of the librarians, information specialists, and software developers exuded, via the discussions and particularly by the examples of the work they were doing at their institutions. Beyond just creating software, this project is poised to enhance the quality and compatibility of spatial metadata to keep our growing pile of geospatial stuff find-able.